Tank destroyer battalion (United States)
The tank destroyer battalion was a type of military unit used by the United States Army during World War II. The unit was organized in one of two different forms—a towed battalion equipped with anti-tank guns, or a mechanized battalion equipped with armored self-propelled guns. The tank destroyer units were formed in response to the German use of massed formations of armored vehicles units early in WWII. The tank destroyer concept envisioned the battalions acting as independent units that would respond at high speed to large enemy tank attacks. In this role, they would be attached in groups or brigades to corps or armies. In practice, they were usually individually attached to infantry divisions. Over one hundred battalions were formed, of which more than half saw combat service. The force was disbanded shortly after the end of the war when the concept had been shown to be militarily unsound.
Doctrine development
In April 1941, a conference focused on the future of antitank operations. The immediate effect was to create an anti-tank battalion in infantry divisions, but this organic anti-tank capacity was not deemed sufficient. The conference gave broad support to the idea of creating mobile anti-tank defensive units which could be deployed to meet an armored attack. The effort stalled on the issue of which branch of the Army should control it—the infantry, the cavalry, or the artillery. The Armor Branch did not press for control of the anti-tank units, feeling that it would be at odds with their general principles of maintaining the offensive. In May, General George C. Marshall "cut through the knot" by declaring the issue as sufficiently important to be dealt with as a combined-arms organization, forming an Anti-Tank Planning Board headed by Lt. Col. Andrew D. Bruce, and appointing Brigadier General Lesley J. McNair to take immediate action on organizing anti-tank forces.Three anti-tank "groups" were quickly organized, with each consisting of three anti-tank battalions drawn from personnel of infantry divisions and various support units, and tasked with "speedy and aggressive action to search out and attack opposing tanks before they had assumed formation". In August, a plan was laid out for a program of 220 anti-tank battalions.
The first nine units were deployed during the Louisiana Maneuvers of 1941, equipped with towed 37 mm M3 anti-tank guns and surplus 75 mm M1897 guns mounted on half-tracks, and again in the Carolinas maneuvers that November. Their employment was judged a success—though not without some disgruntled voices in the Armored Branch arguing that the umpires had rigged the results — and on 27 November, Marshall ordered the establishment of a tank destroyer Tactical and Firing Center at Fort Hood, Texas, under Bruce, and the activation of 53 new anti-tank battalions under the command of General Headquarters. The term "tank destroyer" was used from this point on, as it was seen as a more psychologically powerful term. On 3 December, all existing anti-tank battalions were reassigned to General Headquarters and converted to tank destroyer battalions.
The new tank destroyer doctrine was formally stated in Field Manual 18–5, Tactical Employment, Tank Destroyer Unit, in June 1942. It laid down a focused doctrine— "There is but one objective of tank destroyer units… the destruction of hostile tanks" —and repeatedly emphasized an offensive, vigorous spirit. Tank destroyer units were expected to be employed as complete battalions, held in reserve and committed at critical points, rather than parceled out as small defensive strongpoints. The emphasis was heavy on mobility, and the ability to outmaneuver the attacking armor; this would feed into vehicle design, and cause the speed of a vehicle to be prioritized over survivability.
One side-effect of the new status of the tank destroyer force was that, as a fully-fledged independent branch, it was required by War Department policy to establish units manned by African Americans – the United States Army remained racially segregated until the Korean War, but the War Department placed pressure on the Army to ensure that a fair proportion of combat units were black. Two of the initially converted battalions were black, with another four created in 1942 and four in 1943. Several would eventually see combat, and the 614th Tank Destroyer Battalion would become the first black unit to receive a Distinguished Unit Citation.
Tactics
US tank destroyer doctrine was essentially a defensive and reactive measure. Their role was to slow down, or even stop, a Blitzkrieg style armored thrust and prevent it from penetrating too deeply or from encircling friendly forces in a pincer movement. The idea was that, once an enemy armored thrust was expected to break through, the tank destroyer battalion, would position itself to intercept the enemy while a more complete defense is organized at corps or higher level. This was to be the case for both towed and mobile tank destroyer battalions. As the enemy armored thrust approached, organic reconnaissance units would communicate to battalion commanders the best locations for tank destroyer units to place themselves in, while organic pioneer units would create blockades or help the tank destroyers dig into their positions. As the enemy armored thrust came within range, the hidden tank destroyer units would fire upon enemy tanks and then retreat to another position once they began to draw fire.In the offense, mobile tank destroyers were not given the duty to hunt down enemy tanks, as this would be the role of their own tanks. Instead, they were to be positioned close to the advance to stop any counter-attacking armored force. Towed tank destroyer units had no offensive role in an armored thrust, and were given the task of supporting infantry units or being used as indirect fire units to augment artillery. Mobile tank destroyers were also allowed to support infantry operations, or even function in an indirect fire role, so long as their main mission was not compromised.
In terms of vehicle design, mobile tank destroyers were to be heavily armed, but with speed given priority over armor protection. Unlike tanks, mobile tank destroyers were not designed to survive hits from enemy AP rounds, but to mainly resist small arms fire. Crews were also trained to hide their vehicle from enemy fire.
Organization
Three initial organizations were laid down in December 1941; two were light organisations equipped solely with 37mm guns, and were abandoned as soon as possible to standardise on the third type, modeled after the 893rd Tank Destroyer Battalion, and officially declared the standard organization with the publication of FM 18–5 in June 1942. This was designated the "tank destroyer battalion, heavy, self-propelled", and consisted of:- A headquarters company
- A reconnaissance company,
- Three tank destroyer companies of twelve vehicles each
The battalions deployed to North Africa used this organization, with both heavy and light anti-tank guns, but as reports from Europe indicated that light anti-tank guns were no longer playing a significant role in combat, the light platoons were converted to a third "heavy" 75mm gun platoon under a new organization issued in November 1942. As M10 tank destroyers came into use, with a 3-inch gun, these replaced the 75mm gun-equipped M3 GMCs.
By 1943, the role of tank destroyer battalions was becoming better understood, and the early ideas of mass employment of tank destroyer units had become obsolete. As a result, the number of battalions planned was steadily reduced, and the manpower and equipment assigned to them was reduced. A new table of organization produced in January 1943 reduced the overall manpower by 25%, by eliminating the anti-aircraft units, reducing the number of supporting units, and combining the tank destroyer platoon's headquarters with its security section. There was no reduction in actual combat strength.
In early 1943, stemming from problems found in North Africa, the Army began to consider a more defensive role for tank destroyer units. After trials in January, fifteen battalions were ordered to convert to towed guns on 31 March, and shortly thereafter it was decided that half of all tank destroyer units would convert to a towed organization. The broad outline of the battalion remained – three companies of three platoons of four guns – but the reconnaissance company was downgraded to two platoons in the headquarters company. However, the need for larger gun crews and more security troops meant that the manpower of the unit increased again. These units were equipped with 3-inch M5 guns towed by trucks or M3 Halftracks. However, combat experience in Normandy and in Italy – coupled with the fact that purpose-built M18 Hellcat and M36 tank destroyers were becoming available – showed that the towed units were underperforming compared with self-propelled ones. After the Ardennes campaign, where 85% of all tank destroyer losses were towed guns, it was decided to convert all towed units back to self-propelled guns.
Reconnaissance and pioneer units
The Reconnaissance company of the tank destroyer battalion was made up of three reconnaissance platoons and one pioneer platoon, along with supporting units.The reconnaissance platoons had two main missions for the battalion's tank destroyer units: "Route reconnaissance, particularly of those routes over which the gun companies will move to reach combat areas", and "Area reconnaissance, particularly to locate general areas suitable for use as combat areas by the gun companies". Other missions included zone reconnaissance, battle reconnaissance, security missions and counter-reconnaissance. Each platoon had two M8 Greyhound armored cars and five 1/4 ton trucks. In the context of Tank Destroyer doctrine - that the battalion be placed in the path of an enemy armored thrust - the reconnaissance platoons served to seek and locate areas for tank destroyer units to set up.
The pioneer platoon had two general missions: to prevent the movement of the battalion from being delayed by natural or artificial obstacles, and to impede or canalize the movement of the enemy by the creation of obstacles. The pioneer platoon consisted of a platoon headquarters and two sections, each section included ten men and two -ton trucks equipped with pioneer tools and equipment; the platoon headquarters consisted of six men, an M20 armored utility car, and an air compressor complete with all its various air powered tools.
Since neither the pioneer nor reconnaissance units were able to function as originally intended, they were often attached to other units that operated under the division or corps that the tank destroyer battalion had been assigned to.